The elimination of gentamicin-resistant gram-negative bacteria in a newborn intensive care unit

The aminoglycosides play a central role in the treatment of infectious diseases caused by gram-negative bacteria. During the period of January to June 1984, 45 clinical specimens collected in our neonatal intensive care unit grew Enterobacter cloacae; 41 of them were gentamicin resistant. One neonate developed septicemia. The routine antibiotic protocol was then changed from gentamicin-ampicillin to amikacin-ampicillin for a period of six months. During this period the resistance to gentamicin declined to a minimum. Only eight of 122 specimens proved to harbor gram-negative organisms resistant to gentamicin. The gentamicin-resistant E. cloacae vanished. No isolate was resistant to amikacin. The gentamicin-ampicillin regimen was then reintroduced.